Feed product and method of producing same



Jan- 17, 1961 B. H. THURMAN 2,968,559

FEED PRODUCT AND METHOD OF PRODUCING SAME Filed Dec. 30, 1958 5am 0R Bzmva 12/? 10 35 a4 [xr/mcr 36 New. 7/3

V Bag 5, lawfxczss Paar/2m Essa Pxooucr United States Patent-O FEED PRODUCT AND METHOD OF PRODUCING SAME Benjamin H. Thurman, New York, N.Y., assignor to Benjamin Clayton, doing business as Refining, Incorporated Filed Dec. 30, 1958, Ser. No. 784,843

18 Claims. (Cl. 99-2) This invention relates to animal feed products and to novel processes of producing same. More particularly, it relates to feed products which are mixtures of meal and alkali soapstocks produced in the refining of crude glyceride oils. The present application is a continuationin-part of my prior applications Serial No. 553,312, filed December 15, 1955;, now abandoned; Serial No. 529,708, filed August 22, 1955, now abandoned; and Serial No. 481,930, filed January 14, 1955, now Patent No. 2,876,242.

Crude glyceride oils are extracted from seeds, nuts or beans by pressing or by the action of solvents or by both, leaving a residual meal which is often used as an animal feed product. Particularly when employing solvents to extract the oil the residual meal is very low in fat content, usually containing less than 1% residual oil, as compared with upwards of 4% in meal produced when the oil is expressed by pressing. There have been many proposals to fortify meals of both types with animal fats, free fatty acids, etc. The proposals have not been widely utilized because of the costs involved and because the resulting feeds leave much to be desired.

The crude glyceride oils thus produced contain "in varying relative amounts free fatty acids and gums, the latter including phosphatides and pigments such as carotine, xanthophyll, etc. Such crude oils are refined by mixing therewith alkali in predetermined excess based on the amount theoretically required to react with the free fatty acids. Such reaction produces fatty acid soaps. In addition, the alkali solution also precipitates the gums of the oil. If caustic soda is employed as the alkali, the caustic reacts also with some of the oil, forming additional soaps. Use of caustic soda in excess of stoichiometric amounts degrades or destroys the phosphatides of the gums. If soda ash is used as the alkali there is no reaction with the oil itself. If the amount of soda ash is in low excess, e.g., no more than about three times the amount required to react with the free fatty acids, there is substantially no alkali degradation of the phosphatides.

If the oil-alkali mixture is settled or centrifuged, the reaction products and the precipitated gums are separated as alkali soapstock. Low-excess soda ash soapstocks have heretofore been of little value, having a total fatty acid content too low to justify shipping. Caustic alkali soapstocks are often acidulated by adding acid in large excess and settling to produce black grease from which low grade fatty acids can be recovered. Conventional highexcess soda ash soapstocks can be similarly treated but such acidulation is not economic on low-excess soda ash soapstocks produced by the use of an amount of soda ash not substantially in excess of about three times the amount required to react with the free fatty acids. Such soapstocks have heretofore been considered of little commerical value.

It has been found that low-excess soda ash soapstock can be added to animal feeds with quite unexpected results. Being complex mixtures of soap, free alkali, gums,

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coloring matter, etc., those skilled in feed formulations would normally avoid such nondescript mixtures in animal feeds. For example, soaps in significant amounts in feeds have usually been avoided because of the scouring action they have on the animal. Free alkali in feeds adds to the inorganic salt content thereof and makes the meal unpalatable, not to mention the undesirable neutralization of stomach acids needed for digestion. The present invention is based in part on a finding that the unique balance of the components of low-excess soda ash soapstock make this material unexpectedly beneficial as a feed additive. It is an important object of the invention to add about .25% or more of low-excess soda ash soapstock to animal feeds.

Crude glyceride oils are usually extracted from the seeds, nuts or beans in an oil mill which sells its meal as an animal feed product and which ships its oil to an oil refiner who alkali-refines it and must acidulate or dispose of the soapstock by-product. By the present invention, the oil mill can employ a solution of soda ash to treat the crude oil, often while still at superatmospheric pressures or while containing residual amounts of solvent, to produce a soapstock that can be returned to the indigenous meal to increase its fat content and greatly improve its nutritive value. At the same time, the oil mill produces a refined or partially refined oil that is easily further refinable with low losses to meet specifications of color, free fatty acids content, stability, etc., an oil of such high quality as to command a premium in the market. It is another object of the invention to revise the economics of present practices in the industry in these manners.

Many advantages arise from a sequence in which the low-excess soda ash soapstock is mixed with the feed product before the latter is heated to drive off residual solvent or moisture. Uniform mixing is made easier by this sequence and it becomes possible to employ the conventional drying or desolventizer equipment to form the mixture. It has also been found that the temperatures commonly used in such equipment, typically -120" C., can be made to effect a detoxification of a mixture in which the meal and/ or the soapstock are from cottonseed and contain free gossypol. In this connection it has been found that while temperatures in excess of 130 C. are required to detoxify the soapstock alone, it can be detoxified at temperatures of about IOU- C. in admixture with a meal. Likewise it has been found that gossypol-containing meals can be detoxified at lower temperatures if soapstock is present therein. Specifically, cottonseed meals that are not appreciably reduced in gossypol content by the temperatures and conditions in a conventional desolventizer can be substantially detoxified therein if in admixture with a minor portion of soapstock. It is an important object of the invention to mix soapstock with a meal or other feed product and subsequently aggl ycheat to a maximum temperature of about 100- It is another object of the invention to provide new feed products of unique properties which products contain minor proportions of low excess soda ash soapstock.

Other objects and advantages will become apparent to those skilled in the art from the following discussion of general factors and specific examples.

Suitable source materials for the present process are soya beans, cottonseed, corn, peanuts, or other vegetable materials from which crude vegetable oil such as soya, cottonseed, corn, peanut, linseed, palm, safilower, sunflower, etc. may be extracted by pressing or solvent actions. The crude oils will contain gums in varying amounts in addition to the usual free fatty acid content. One of the characterizing features of the invention is that these gums are not substantially degraded by the alkali treatment and that soapstock containing such whole gums is mixed with a feed product. Low-excess soda ash soapstocks contain such gums substantially in the form in which they were present in the sourceoil or at least without substantial degradation through chemical action. The soapstocks returned to the meal should also preferably include a small but limited amount of free alkali as well as a limited amount of soap, the latter resulting from the reaction of the alkali and the free fatty acids as distinct from soaps that would be the result of reaction between a caustic alkali and the oil itself.

It has been found that when relatively small excesses of soda ash are mixed with the crude vegetable oils, usually as an aqueous solution of a strength of about 16-30 B., the gums will be precipitated and the free fatty acids will be reacted to an extent determined by the amount of soda ash used and the subsequent steps in the process. Present commercial soda ash oil refining processes employ soda ash in amounts substantially exceeding three times the amount theoretically required to react the free fatty acids, excesses of 5-8 being most commonly employed but excesses up to 12 times being sometimes used. The resulting soapstocks contain large amounts of free soda ash, are not substantially completely soluble in petroleum ether and are not suitable for incorporation into feeds in any substantial quantity. In contradistinction, the present process employs an amount of soda ash ranging from a fraction of the amount theoretically required to neutralize the :fatty acids up to but no more than about three times such amount. An amount no more than about twice that required to neutralize the free fatty acids is usually preferred, the preferred range being about 1-2 times the amount required to react the fatty acids.

The low-excess soda ash soapstocks with which this invention is concerned are preferably produced from crude glyceride Oils containing significant amounts of gums. Low-excess soda ash soapstocks are carbonated vegetable phospholipids, being complex mixtures of fatty acid soaps, free alkali, gums or 'phosphatides, coloring matter, oil and Water. As contrasted with caustic soapstocks or high-excess soda ash soapstocks, they are substantially completely soluble in petroleum ether, evidencing that the gums therein, including the phosphatidic complexes of the crude oil, are largely in the same form as in the oil and that there has been substantially no alkali degradation thereof. Such soapstocks are stable and nonfermenting. Compositional ranges, dry basis, are approximately as follows:

Percent Soaps About -45 Gums (primarily phosphatides) About- 20-65 Free alkali (soda ash) About l-10 Oil About 12-25 As separated, such soapstocks are of relatively. low moisture content, usually containing less than 45% and often less than 35% water by weight, unless water is deliberately added during the separation. Factors relating to these components and the differences between lowexcess soda ash soapstocks and water-precipitated gums or other soapstocks are discussed in the following paragraphs.

The soaps of the soapstock are desirable free fatty acid soaps and not undesirable soaps resulting from the re to the later-mentioned action of the soapstock in avoiding bloat. The character of these soaps appears to differ from ordinary soaps. The latter are not soluble in petroleum ether while the soaps and other components of low excess soda ash soapstock are substantially completely soluble therein.

The gums in the soapstock are of importance. The usual low excess soda ash soapstock with which the invention is concerned contains substantially all of the gums of the crude oil substantially free of alkali degradation, being thus distinct from the gums in caustic soapstocks or in high-excess soda ash soapstocks particularly when aged or oxidized. The carbonated nature of the gums in this soapstock contribute to their effectiveness in feed products. The best feed products result from low excess soda ash soapstocks separated from crude oils high in gums but such soapstocks from oils of lower gum content are only slightly less effective. The gums are largely phosphatides comprising a complex mixture of lecithinic, cephalinic, inositide and other phosphorus compounds. Crude oils contain from 0.75% to 3.0% of these gums.

The gums in crude oils are commonly considered as including some of the pigmenting materials or color components thereof. Some of these appear in the lowexcess soda ash soapstock and some remain in the separated or partially refined oil. Those remaining in the low-excess soda ash soapstock are of particular significance in feeds. For example the carotinoid pigments, which include carotines and xanthophylls, of soya, palm and other oils are important in feeding chickens where these materials increase the desirable yellow color of the fat. In these respects the low excess soda ash soapstock of the invention is in marked contrast to the gums separated from the same oils by water degumming steps or in foots separating from such oils on long standing. Such soapstock contains about 3-5 times as much carotinoids as such other gums. For example it is not uncommon to find about mg./lb. carotinoids in low excess soda ash soapstock from soya oil and about ing/lb. from palm oil, as compared respectively with about 20 and 30 mg./lb. in water precipitated gums or gums otherwise separated from these oils.

The low excess soda ash soapstock contains a small amount of free alkali sufficient to increase the surface active properties of the phosphatidic complexes but insufficient to influence materially the inorganic salt content of the meal or make it unpalatable or unsuited for use in feeds. In fact, the free alkali content of low excess soda ash soapstock is unexpectedly beneficial in feeds in conjunction with the other soapstock components. This is in contradistinction to the large amounts of free alkali in the older high-excess soda ash soapstocks which may contain as high as 15% free alkali or more, dry basis, and therefore cannot be added in toto to the meal from which the source oil was extracted. Caustic soapstocks contain no significant amounts of free alkali as any free alkali tends to react with the oil to form soaps. Low excess soapstocks resulting from the use of soda ash in excesses not greater than about three times the amount to neutralize will ordinarily contain 5% or less of free alkali. The preferred alkali content is about 25% and never beyond l-10% by weight, dry basis. Depending upon the excess of soda ash used and the operating conditions of the process, a minor or major part of this small fraction of free alkali may be sodium bicarbonate. The free alkali and the soapstock combines with some of the protein in the meal to form complexes that are more soluble in water and stomach fluids and more easily digested than the protein that is not so combined.

The oil content of low excess soda ash soapstocks is significant to the invention, being present in amount particularly suited to feeds while not being present in such emanate. as to. mak t e o er l pro es une aami through undue losses of the valuable refined oil produced. The oil increases the nutritive value of the feed and its assayable fat content. It aids in fluidizing the soapstock and the mixing thereof with the meal. The oil content of such soapstock is significantly different from water precipitated gums which if centrifugally separated will contain about 35-40% oil, dry basis, representing an uneconomic operation compared with the low excess soda ash refining of the invention. Gravity separated water precipitated gums or caustic or soda ash soapstocks are even higher in free oil than the corresponding centrifugally separated products.

In general, the addition of low-excess soda ash soapstocks to meals to form a feed product has many advantages. Minor amounts of such soapstocks will decrease dusting and markedly better the pelletizing properties of meal while also bettering the color, increasing the nutritive qualities, making the food product more palatable, and stimulating the appetite of the animal even in hot weather when cattle, for example, eat less than in cool weather. By way of example, solvent extracted cottonseed meal is converted from a dusting, non-pelleting, whitish, nutritionally-deficient meal to a nondusting, readily pelletizable, desirably yellow-colored, high-grade, nutritionally enhanced meal by the addition of minor amounts of low excess soda ash soapstock.

The fortified meal will assay at least as much increase in fat as there are phosphatides and free oil in the soapstock, due to the fact that the low excess soda ash soapstock is substantially completely soluble in petroleum ether. For example, adding 3% soda ash soapstock, dry basis, containing 50% phosphatides and 20% free oil, will increase the fat content by approximately 2.1%.

The feed products of the invention when ingested by cattle disperse quickly in the stomach or paunch, the soapstock serving to keep the meal or other ingredients suspended so that digestion proceeds uniformly. The condition known as bloat, in which the feed products sink to the bottom of the stomach and gas accumulates on top thereby choking the animal, is entirely avoided. The gas evolution is homogeneous throughout the well-dispersed meal products, which are in turn kept in suspension by the surface-active properties of the soapstock.

The bloat-preventive property of low excess soda ash soapstock has been shown to be significant in feeding tests. For example, in one instance an animal that had bloated in a previous experiment when fed green forage had no bloating difiiculty when fed a control plus a small amount of low excess soda ash soapstock.

It has also been shown by in vitro tests that low excess soda ash soapstock significantly decreases the surface tension of rumen fluid. This may be in part responsible for the bloat-preventing properties of the material. In typical in vitro tests, rumen samples mixed with low excess soda ash soya soapstock and with low excess soda ash cottonseed soapstock showed the following results:

It has been observed in feeding tests that low excess soda ash soapstocks added to the control have a definite tendency to increase the digestibility coefficients of the animals. For example, as between a control ration of 40% ground peanut hulls, 50% ground yellow ear corn and cottonseed meal and the control ration containing l /2% low excess soda ash cottonseed soapstock, digestibility coefiicients for dry matter averaged respectively 43 and 49, for protein averaged respectively 61 and 69 and for energy averaged respectively 40 and 48. Similar results are not obtainable from l-2% commercial lecithin which when added to hay ration showed no improvement in digestibility coefficients.

In the practice of the present invention, substantial economies and better products result from the mixing of indigenous meals and soapstocks. Thus, the extracted crude oil is mixed with alkali and the resulting soapstocks are centrifugally or otherwise separated, being then returned in whole or in part to the meal which was produced when the oil was extracted. In the usual practice, it is possible to reuse all of the soapstock produced in the alkali refining by use of soda ash in low excess. In some instances, it is even possible to add to the meal additional quantities of soapstocks or gums, preferably althrough not necessarily from the same type of oil.

The proportions of meal and soapstock in the feed product are not critical, albeit the meal should always constitute a major portion and the soapstock a minor portion of the mixture. Beneficial results will accrue from the use of an amount of low excess soda ash soapstock ranging from a fraction of a percent up to 10% or somewhat higher, percentages being expressed by weight on a dry basis. The amount of soapstock will depend in part upon the purpose for which it is added. Amounts as low as about .75-1.5% will prevent dusting. Amounts of about .753% or more will improve the pelleting properties of the meal, imparting a desirably shiny, glazed appearance to the product. Amounts of about l5% or higher will desirably increase the nutritive value and will not detract from the desirable pelletizing and nondusting properties.

In general, except for very high-loss oils, the indigenous soapstock available for addition to the meal will not exceed about 5% when the refining process is employed efficiently. On most oils, the amount of indigenous soapstock would be no more than about 2% of the weight of the meal. If larger amounts of soapstocks are desirable in the meal, nonindigenous soapstocks can be added.

The soapstock can be added to and mixed with the meal in any desired manner. It is particularly advantageous, however, to employ existing drying or desolventizing equipment in this connection. Particularly when the crude oil is extracted with the aid of solvents,

the meal contains residual moisture and a residual amount of the solvent, these volatile materials being conventionally removed in a desolventizer. It is distinctly preferable to add the low excess soad ash soapstock to the meal at a position ahead of or within the desolventizer so that the soapstock is present to aid in the mixing and when the solvent-vaporizing. and water-vaporizing temperatures are present. However, low excess soda ash soapstock readily and thoroughly penetrates or mixes with the meal to give a homogeneous product irrespective of whether it is added before or after desolventizing. The surface-active properties of the soapstock facilitate this action.

In some instances, it is desirable to mix the soapstock with some other material before adding it to the meal or to mixed feeds. In this respect it is often desirable to augment the normal water content of the separated low excess soda ash soapstocks (normally about 30-40% by weight) by adding additional water thereto during or after the separation. Any amount of water is effective in this regard and it is sometimes desirable to add up to three parts of water or more to one part of soap-stock, by weight. In addition, molasses or other materials in which the soapstock will disperse can be added thereto before the same is mixed with the meal. For example, a mixture of one part soapstock, two parts molasses, and three parts water, by weight, is fluid and pumpable at room temperature and represents a desirable additive. An animal feed stock comprising a mixture of ear corn, alfalfa hay, soya or cottonseed meal and the low excess soda ash soapstock resulting from the refining of the indigenous soy or cottonseed oil, with or without a small percentage of molasses, will make complete-ration pellets that steers will consume with resulting substantial weight gains. Loose or bulk mixtures of oat and peanut hulls, cottonseed meal and hulls, and low excess soda ash soapstock are usually not completely consumed by the animal but if pelleted will be eaten. Some animals, particularly steers, find it difficult to mouth the bulk ration, as compared with the pellets.

In the processing of cottonseed to extract cottonseed oil, it is well known that both the oil and the meal often contain free gossypol in objectionable amounts. This free gossypol is more or less toxic to animals. The amount of free gossypol in cottonseed meal may vary from about .04 to .6% and in the oil may vary from .03% to as high as .6% or even up to .8%. While the digestive system of cattle may tolerate significant amounts of free gossypol, it being sometimes permissible to feed meals containing .4% free gossypol, other animals such as swine or chicks cannot tolerate any substantial amount thereof in their feed. The free gossypol of cottonseed meal must be below about .04% to be reasonably safe for incorporation in feeds going to swine and it is desirable to reduce the free gossypol content to even lower values, particularly in feed for laying hens to prevent discoloration of egg yolks.

As previously mentioned, the relatively low temperatures conventionally employed in desolventizers are sufficient to detoxify the meal and the soapstock in admixture. The meal can be detoxified at lower temperatures because of the presence of the soapstock and the latter can be detoxified at lower temperatures because of the presence of the meal. The observed fact that the mixture of meal and soapstock can be detoxified at lower temperatures than would be necessary if either component 'were treated alone is not predictable on the basis of prior knowledge.

It is believed that the free alkali content of low excess soda ash soapstock contributes to the effectiveness of the detoxification. Tests seem to indicate that the alkali releases monoethanolamine from the phosphatidic components and that this chemical may be responsible in part for the reduction in the free gossypol of the meal or soapstock found by analysis. However, the detoxification produced by heating a mixture of meal and soapstock is not a result merely of the presence of free alkali. For example, soda ash alone added to meal produces practically no detoxification as compared with the use of low excess soda ash soapstock under the same conditions.

Fig. l of the drawing shows a pipeline diagram of apparatus capable of carrying out the process and producing the feed product of the invention.

Referring to the drawing, the seeds or beans 7 are subject to pressing, solvent extraction or both in the usual oil extraction mill by apparatus 8 which produces crude oil 9 delivered to a container 10, hulls and byproducts 11, and meal designated by the numeral 12. The alkali refining agent, typically a 20 B. aqueous soda ash solution, is contained in a tank 13. Proportioned streams of oil and alkali are forced by pumps and 16, adjustably driven by a suitable drive 17, to a junction 20. The oil and the alkali may, if desired, be preliminarily heated in the tanks 11 and 13 or in heat exchangers 21 and 22.

The mixed stream from the junction may flow through a heat exchanger 24 for further adjustment in temperature, with or without use of a mixer 25 to mix the oil and the alkali more intimately than is accomplished at the junction 20. The heat exchanger 24 may have a number of sections, if desired. The resulting heated mixture flows directly or after intervening steps to a separating means shown as a centrifuge from which the oil is continuously discharged through a spout 27 and from which the soapstock is continuously discharged through a spout 28. Separation will usually be at superatmospheric temperature, typically about 180-210 F.

If separation is effected in the usual open centrifuge it may be desirable to remove CO from the mixture before it enters the centrifuge, as suggested in my Patent No. 2,876,242. Alternatively, many advantages arise from the use of centrifuges of the closed type in which the effluents are restricted to maintain a high superatmospheric pressure in the rotating equipment. In this instance a high superatmospheric pressure is maintained during the separation and no CO need be separated. The low-excess soda ash soapstock from the latter process is sometimes known as pressure soapstock and is par ticularly well suited to the purposes of the invention.

If the meal 12 contains residual solvent, the separated soapstock may be mixed therewith continuously or batchwise either before or after the solvent is removed, the former being distinctly preferable. Thus, by opening a valve 29, the soapstock may be pumped by a pump 30 to a paddle-type mixer 31 receiving the meal 12. The gums mix readily with the meal therein.

The resulting mixture is sent to a heater, exemplified as a conventional desolventizer 32. Alternatively the soapstock passing the valve 29 may be delivered directly to an early stage of the desolventizer 32. Such desolventizers progressively heat the mixture in stages, steam being conventionally applied in the last stage or stages. The meal reaching the desolventizer commonly contains upwards of 10% moisture, the moisture content commonly varying between about 5% and about 15%. If the meal has been solvent extracted, the mixture may contain about 25-35% of residual solvent, sometimes more. The temperatures in the desolventizer are sufficient to vaporize at least a portion of the solvent and the moisture, the resulting vapors being removed as indicated at 33. Additionally, the temperatures employed in the desolventizer are suflicient to detoxify cottonseed meals or soapstocks if these are a part of the mixture therein.

The resulting feed product 34 from the desolventizer may be used as such, as indicated by the numeral 35, or may be sent to a pelletizer 36 of conventional construction for the production of pellets 37 constituting the feed product. In either instance, it will be understood that the meal-type feed product will usually be fed as a part of a complete dietary program, being usually mixed with other feeds, such as corn or grains, either by the mixed feed manufacturer or the ultimate user.

In the desolventizer 32, the meal is agitated during the heating to facilitate uniform vaporization of solvent and water. If the object is primarily to remove the vapors, temperatures of about 931 16 C. can be employed at substantially atmospheric pressure or even lower temperatures can be employed if a vacuum is maintained on the desolventizer. However, if detoxification is to be accomplished, temperatures of about -l20 C. will be found best.

For detoxification, the duration of the heating is not critical. The residence time in conventional desolventizing equipment will suffice for detoxification as the mixture will be maintained at a temperature of 100120 C. for at least several minutes. Total heating times of 15 minutes up to 2 hours have been employed with success.

In the event it is desired that the residual solvent in the meal 12 should be removed before adding the soapstock, the meal 12 can by-pass the mixer 31, as indicated by the valved by-pass 39, and move directly to the desolventizer 32 and thence through a pipe 40 to a mixer 42. By opening a valve 43 and closing the valve 29, the soapstock can be delivered to the mixer 4-2 to produce either the meal-type feed product 35 or the pellettype feed product 37 previously mentioned. In this instance, at least a part of the solvent and water in the meal 12 is removed in the desolventizer, the moisture in the soapstock remaining in the feed product.

If the meal 12 contains no solvent, it can by-pass the mixer 31 through the valved by-pass 39 and the desolventizer 32 through a valved by-pass 45, being delivered directly to the mixer 42 where it is mixed with the aforesaid soapstock. In such instance, it may sometimes be desirable to heat the product in the mixer 42 both to facilitate mixing and to adjust the water content of the meal-type or pellet-type product.

It is sometimes desirable to add water or other material such as molasses to the soapstock before mixing same with the meal. This may be done batchwise or by adding a pumped stream to the separated soapstock as indicated by the numeral 46. Water added at this point facilitates uniform mixing of the soapstock with the meal. Also, adding water to the soapstock during or after separation makes them more pumpable. For example, adding to the soapstock an equal weight of water is often desirable. Even more water can be added if the soapstock is to be mixed with the meal after desolventizing thereof, but if added to a meal while still containing residual solvent, little or no water need be added, particularly if the meal is at a temperature of 65 C. or higher, as the solvent can readily dissolve the soapstock.

All of the aforesaid equipment will desirably be installed at the oil extraction mill. This is desirable for several reasons. In the first place, it insures that the meal and soapstock used in producing the feed product will be relatively fresh as is desirable. It has been found that detoxification is much more effective if the meal is freshly produced. Attempts to detoxify meals that have stood for several weeks will produce little detoxification as compared with meals that have been produced within a matter of days or hours. In the second place, the oil 27 can be sold for premium prices even if it is not comletely refined. For example, it may contain color impurities or some of the free fatty acids and will thus be sold as a crude oil, albeit at premium prices because of the low cup loss, i.e., the low loss of oil that will be experienced in completing the refining operation. In the third place, the steps of the invention represent a unitary operation in which two low-valued products can be most economically brought together if produced in the same locale. In the fourth place, the economics of oil milling are greatly improved by the ability to dispose of the meal as a high quality feed product.

In low-excess soda ash processes the fatty acid content of the separated oil will be higher than if the same excess of caustic soda was used. This separated oil usually contains 0.060.12% residual fatty acids and some coloring materials, making it desirable to re-refine same by use of caustic soda as disclosed in US. Patent Re. 23,680. However this can be done with very low losses and the separated oil from which the soapstock has been separated is of high-grade and commands premium prices.

Example A The process will be first exemplified as employing soda ash mixed with the oil in amount not substantially in excess of three times the amount necessary to neutralize the free fatty acids of the oil and preferably in amount ranging from a fraction of that required to neutralize up to about twice that required to neutralize. In a typical operation, soya beans were solvent extracted from the beans to produce a crude soya oil containing 1.41% free fatty acids and very high in pho-sphatides. The resulting crude oil was partially refined by preheating it in flow to 180 F. and mixing therewith an amount of soda ash substantially equal to 1.5 times the amount required to neutralize the free fatty acids, the soda ash being added as a 20 B. solution. The mixture wascooled to 10 about F. and separated in a suitable centrifuge. The separated low excess soda ash soapstock contained about 25.0% free oil, dry basis, and about 20.0% water, the remainder being gums, soaps resulting from the reaction of the soda ash and the free fatty acids, and a small amount of free alkali. The soapstock assayed 1.92% phosphorus, dry basis. Three ounces of such low excess soda ash soapstock added daily to a control meal showed average weight gains in heifers of 87.5 lbs., as against a gain of 65 lbs. on heifers feeding on the control ration, in a test of our Weeks duration.

Example B In other tests, cattle fed for fifty-six days on a ration including 22.5% solvent extracted cottonseed meal showed an average daily gain of 1.75 lbs. As compared with this control, cattle fed for the same period with the same meal to which 2.5% of low excess soda ash soapstock from crude cottonseed oil was added, showed an average daily gain of 2.22 lbs. Feeding tests with other animals, including chicks and rats, have shown similar unexpected results.

Example C In other tests, steers gaining an average of 1.81 lbs./ day on a control ration, on an average intake of 20.7 lbs./ day (giving a value of 1147 lbs. of feed per 100 lbs. of gain in weight) were compared with steers on the same control plus 1.5% of low excess soda ash soya soapstock and with other steers on the same control plus 1.5% of low excess soda ash cottonseed soapstock. With the soya soapstock additive, the average gain was 1.86 lbs. With the cottonseed soapstock additive, the average gain was 2.13 lbs. and the average intake was 21.5 lbs. (requiring only 1009 lbs. of feed per 100 lbs. gain. These tests were on drylot feeding for days.

Example D In other drylot feeding tests of the type in Example C, steers fed on a control ration gained an average of 2.30 lbs./ day at an intake of 22.5 lbs. With 1.5% low excess soda ash cottonseed soapst-ock added to the control, comparable steers gained an average of 2.47 lbs./day at an intake of 23.3 lbs. The feed requirements per one hundred lbs. gain were reduced respectively from 980 to 943.

Example E To 100 parts of a solvent-extracted cottonseed meal containing 0.41% free gossypol, dry basis, was mixed 3.0 parts, dry basis, of a low excess soda ash cottonseed soapstock containing 1.44% free gossypol, dry basis. The soapstock was in this instance mixed with 15 parts of water before being added to the already desolventized meal. The mixture was placed in a jacketed closed-type mixer. After mixing for a period of about 15 minutes at room temperature, the temperature in the jacket was raised rapidly to 107-1 10 C., the mixing being continued for 30 minutes at this temperature. Thereafter, the mixing vessel was opened and the excess moisture evaporated from the mixture during a 15-minute additional mixing time. The resulting feed product contained 0.026% free gossypol, corresponding to 0.028% dry basis.

To show that the soda ash alone is not effective for detoxification, the above solvent-extracted cottonseed meal was mixed with 0.33% sodium carbonate dissolved in 16% water, both percentages based on the weight of the meal, and treated under the same conditions as above. The resulting meal assayed 0.26%. free gossypol, dry basis. The same meal heated under the same conditions in the presence of Water alone was reduced only to 0.31% free gossypol, dry basis.

Example F To 100 parts of a solvent-extracted cottonseed meal containing 0.059% free gossypol, dry basis, was muted 3.0 parts of a low excess soda ash cottonseed soapstock containing 1.44% free gossypol, dry basis, dispersed in 15 parts of water. When treated as in Example E, the feed product contained 0.021% free gossypol, dry basis. The petroleum-ether-soluble matter or fat in the meal before admixing the soapstock was 0.23%. After admixing the soapstock and processing as above, the petroleum-ether-soluble matter assayed 2.4%.

In commercial operation, it is not necessary or desirable to use as much water with the soapstock as indicated in these examples. This is particularly true if the soapstock is mixed with the meal while still containing solvent.

Various changes and modifications will be apparent to those skilled in the art from the exemplary embodiments herein set forth and fall within the scope of the present invention. For example, the effectiveness of the low excess soda ash soapstock in meals is not destroyed by the presence therein of small amounts of other materials which do not destroy the property of the soapstock in being substantially completely soluble in petroleum ether nor its content of gums substantially free of alkali degradation soap free alkali and oil.

I claim as my invention:

1. A process for producing an animal feed product, which process includes the steps of: mixing with a glyceride oil containing free fatty acids and gums an amount of soda ash suificient to precipitate said gums and to react with at least some of said free fatty acids to form soap, said amount of soda ash being no more than about three times that theoretically required to neutralize said fatty acids; separating from the mixture a soapstock containing said soap and said gums, said soapstock being substantially completely soluble in petroleum ether; and mixing a minor portion of said soapstock with a major portion of a glyceride oil meal.

2. A process as defined in claim 1 in which the amount of soda ash is about 1-3 times the amount theoretically required to neutralize the free fatty acids of said oil, and in which the meal-soapstock mixture contains about .75- soapstock.

3. A process as defined in claim 2 in which said soapstock contains, dry basis, about 10-45% soap, about 20-65% gums composed mainly of phosphatides substantially free of alkali degradation, about 1-10% free alkali at least some of which is in the form of sodium bicarbonate, and at least 12% of said oil.

4. A process for producing an animal feed product, which process includes the steps of: mixing with a crude glyceride oil containing gums and free fatty acids an amount of soda ash no more than about three times that theoretically required to react with such free fatty acids; separating from the oil a low excess soda ash soapstock comprising the gums of the crude oil substantially free of alkali degradation, soaps resulting from the reaction between said alkali and free fatty acids of the oil as distinct from soaps resulting from reaction between said alkali and the oil itself, about 1'225% of said oil and a small amount of free alkali; and mixing with an animal feed stock a minor portion of such separated low excess soapstock.

5. A process as defined in claim 4 in which said low excess soapstock comprises about 110% free alkali, a portion of said alkali being sodium bicarbonate.

6. A process for producing a feed product and a partially purified oil from a glyceride-oil source material, which process includes the steps of: extracting a crude glyceride oil from said source material while producing therefrom a meal, said crude glyceride oil containing gums and free fatty acids; mixing sufficient soda ash with such crude glyceride oil to react with at least a part of said free fatty acids to form in the oil soapstock comprising gums and soaps, the amount of soda ash being about 1-3 times that required theoretically to react with said free fatty acids of said oil," separating such soapstock to produce said partially purified oil,

said separated soapstock containing about 1-10% free alkali; and mixing substantially all of said separated soapstock with said meal produced in the extraction step to form said feed product.

7. An integrated process for obtaining a vegetable oil from a source material and producing an enriched animal food product, which process includes the steps of: recovering from said source material a crude vegetable oil containing gums and free fatty acids, leaving a particulate vegetable meal of low fat content; recovering from said crude vegetable oil a low excess soda ash soapstock containing the gums of the oil substantially free of alkali degradation, soda ash soaps of the free fatty acids of said oil, and about 110% of free alkali, said soapstock being recovered by steps including mixing said crude oil an amount of soda ash sufficient to react with some of said free fatty acids and pecipitate said gums but not more than about three times that required theoretically to react said fatty acids and centrifugally separating said soapstock from said oil to produce said low excess soda ash soapstock; and returning at least a large portion of said low excess soda ash soapstock to said particulate vegetable meal of low fat content and mixing same therewith.

8. An integrated process as defined in claim 7 in which said meal and said crude vegetable oil contain all of the fatty acids of said source material, and in which said low. excess soda ash soapstock is substantially completely soluble in petroleum ether, said process including the step of heating the mixture of meal and soapstock to a temperature sufficient to remove vapors therefrom and form said enriched animal food product.

9. A process for producing an animal feed product, which process includes the steps of: mixing with a major portion of a vegetable oil meal a minor portion of low excess soda ash soapstock containing soaps and gums resulting from the refining of a crude glyceride oil by the use of an amount of soda ash not more than about three times the amount required theoretically to react said free fatty acids, said soapstock containing a small amount of free alkali, the mixture containing a volatile component including Water; and heating the mixture sufficiently to remove at least a part, of said water.

10. A process for producing an animal feed product, which process includes the steps of: producing from a source material with the aid of an oil solvent a crude glyceride oil and a meal, said oil containing gums and free fatty acids, said meal containing residual solvent; mixing with the crude glyceride oil an amount of soda ash no more than about three times that required to react with said free fatty acids of said oil; separating from the oil a soda ash soapstock substantially completely solable in petroleum ether and containing the gums of the crude oil substantially free of alkali degradation, a small amount of soaps resulting from the reaction of the soda ash with free fatty acids of the oil, significant percentages of said oil, and about 110% free alkali; mixing with a major portion of an animal feed stock comprising said meal a minor portion of said soda ash soapstock, said mixture containing residual solvent and water; heating the resulting mixture sufficient to vaporize said residual solvent; and removing the resulting vapors to produce said animal feed product.

11. A process as defined in claim 10 in which said mixture is heated to a temperature of about 93120' C.

12. An. improvement in the process of extracting from a vegetable source material with the aid of a solvent a crude vegetable oil containing gums and free fatty acids, leaving a residual meal containing residual solvent removed as vapors from a desolventizer, said improvement producing a partially refined oil and combining two byproducts to produce an enriched animal feed product, said improvement including the steps of: mixing with said crude vegetable oil' an amount of aqueous soda ash solu tion sufiicient to precipitate said gums and reactmost ofsaid free fatty acids to produce soapstock separable from the oil to leave said oil in partially refined state, the amount of soda ash being no more than about three times that theoretically required to neutralize said fatty acids and such partially refined oil requiring further alkali treatment to produce therefrom a commercial refined oil; separating the resulting alkali soapstock from the crude oil, the separated soapstock being substantially completely soluble in petroleum ether and containing the gums of said oil substantially free of alkali degradation, the soda ash soaps of the reacted free fatty acids, a minor proportion of said oil, a minor proportion of free alkali, and water, the soaps in said soapstock being substantially free of soaps resulting from alkali reaction with said oil, said separated soapstock constituting one by-product and said residual meal constituting another by-product; returning at least a large portion of the freshly separated soapstock to said particulate meal and mixing same therewith at a position ahead of said desolventizer; and heating the resulting mixture in said desolventizer to a temperature sufficient to remove water vapor therefrom and form said enriched animal feed product.

13. An animal feed product produced by the process of claim 1.

14. The process of claim 1 wherein the mixture of soapstock and glyceride oil meal contains free gossypol and said process includes the step of heating said mixture to a temperature of at least 100 C. but not higher than 120 C. to significantly reduce the free gossypol content of the mixture.

15. The feed product produced by the process of claim 6.

16. The feed product produced by the process of claim 10.

17. The process of claim 6 wherein the glyceride oil source material is cottonseed, the mixture of soapstock and meal contains free gossypol, and said process includes the step of heating said mixture to a temperature of about -120" C. for a time ranging from several minutes up to about two hours to detoxify same.

18. The feed product produced by the process of claim 17.

References Cited in the file of this patent UNITED STATES PATENTS 2,686,794 Clayton Aug. 17, 1954 2,726,155 King et al Dec. 6, 1955 2,740,718 Eagle et al Apr. 3, 1956 2,746,864 Pack et al May 22, 1956 2,838,553 Ayres et a1 June 10, 1958 OTHER REFERENCES Markley et al.: Soybeans and Soybean Products (1951), vol. II, Interscience Pub., New York, N.Y., page 646.

Ault et al.: Chemurgic Digest, December 1954, pages 4, 5 and 19.

UNITED STATES PATENT owner: CERTIFICATION I C@ ECTION Patent No. 1 5 January 1'7 1961 Benjamin Ha Thurman It is hereby certified that error appears in the above numbered paten't requiring correction and that the said Letters Patent should read as corrected below.

In the grant lines 2 and 3 and 12 and in the heading to the printed specificawiion lines 5 and 6 for "Benjamin Clagfzon, doing business as lFieiining Incorporeted",, each occurrence read we Benjamin Clayton, doing business as Refining, Unincorporated; column 6 lines 18 and 19, for "aliohr'ough" read although line 52, for "soad" read soda 3 column 10, line 11 for "0m reed four column 12, line 15, after "mixing" insert, mm with o Signed and sealed this 13th day of June 1961.

(SEAL) Aiiest:

ERNEST Wu SWIDER DAVID L, LADD Aime-Eating Officer Commissioner of Patents 

1. A PROCESS FOR PRODUCING AN ANIMAL FEED PRODUCT, WHICH PROCESS INCLUDES THE STEPS OF: MIXING WITH THE GLYCERIDE OIL CONTAINING FREE FATTY ACIDS AND GUMS AN AMOUNT OF SODA ASH SUFFICIENT TO PRECIPITATE SAID GUMS AND TO REACT WITH AT LEAST SOME OF SAID FREE FATTY ACIDS TO FORM SOAP, SAID AMOUNT OF SODA ASH BEING NO MORE THAN ABOUT THREE TIMES THAT THEORETICALLY REQUIRED TO NEUTRALIZE SAID FATTY ACIDS, SEPARATING FROM THE MIXTURE A SOAPSTOCK CONTAINING SAID SOAP AND SAID GUMS SAID SOAPSTOCK BEING SUBSTANTIALLY COMPLETELY SOLUBLE IN PETROLEUM ETHER, AND MIXING A MINOR PORTION OF SAID SOAPSTOCK WITH A MAJOR PORTION OF A GLYCERIDE OIL MEAL. 